From: Steve Sakoman <sakoman@gmail.com>
Date: Mon, 2 Feb 2009 06:42:23 +0000 (+0000)
Subject: ARM: Add ADS7846 touchscreen support to Overo platform
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=238d8d0139486958c75f8b6c8578a7dd90fea131;p=linux-2.6-omap-h63xx.git

ARM: Add ADS7846 touchscreen support to Overo platform

An upcoming Overo expansion board includes an ADS7846 touchscreen controller.

This patch adds support via the ads7846 driver when enabled in the
kernel config.

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

diff --git a/arch/arm/mach-omap2/board-overo.c b/arch/arm/mach-omap2/board-overo.c
index 0f07b7b553d..cf84c6a872e 100644
--- a/arch/arm/mach-omap2/board-overo.c
+++ b/arch/arm/mach-omap2/board-overo.c
@@ -116,6 +116,66 @@ static inline void __init overo_init_smsc911x(void)
 static inline void __init overo_init_smsc911x(void) { return; }
 #endif
 
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) || \
+	defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+
+#include <mach/mcspi.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
+
+static struct omap2_mcspi_device_config ads7846_mcspi_config = {
+	.turbo_mode	= 0,
+	.single_channel	= 1,	/* 0: slave, 1: master */
+};
+
+
+static int ads7846_get_pendown_state(void)
+{
+	return !gpio_get_value(OVERO_GPIO_PENDOWN);
+}
+
+static struct ads7846_platform_data ads7846_config = {
+	.x_max			= 0x0fff,
+	.y_max			= 0x0fff,
+	.x_plate_ohms		= 180,
+	.pressure_max		= 255,
+	.debounce_max		= 10,
+	.debounce_tol		= 3,
+	.debounce_rep		= 1,
+	.get_pendown_state	= ads7846_get_pendown_state,
+	.keep_vref_on		= 1,
+};
+
+static struct spi_board_info overo_spi_board_info[] __initdata = {
+	{
+		.modalias		= "ads7846",
+		.bus_num		= 1,
+		.chip_select		= 0,
+		.max_speed_hz		= 1500000,
+		.controller_data	= &ads7846_mcspi_config,
+		.irq			= OMAP_GPIO_IRQ(OVERO_GPIO_PENDOWN),
+		.platform_data		= &ads7846_config,
+	}
+};
+
+static void __init overo_ads7846_init(void)
+{
+	if ((gpio_request(OVERO_GPIO_PENDOWN, "ADS7846_PENDOWN") == 0) &&
+	    (gpio_direction_input(OVERO_GPIO_PENDOWN) == 0)) {
+		gpio_export(OVERO_GPIO_PENDOWN, 0);
+	} else {
+		printk(KERN_ERR "could not obtain gpio for ADS7846_PENDOWN\n");
+		return;
+	}
+
+	spi_register_board_info(overo_spi_board_info,
+			ARRAY_SIZE(overo_spi_board_info));
+}
+
+#else
+static inline void __init overo_ads7846_init(void) { return; }
+#endif
+
 static struct mtd_partition overo_nand_partitions[] = {
 	{
 		.name           = "xloader",
@@ -310,6 +370,7 @@ static void __init overo_init(void)
 	usb_ehci_init();
 	overo_flash_init();
 	overo_init_smsc911x();
+	overo_ads7846_init();
 
 	if ((gpio_request(OVERO_GPIO_W2W_NRESET,
 			  "OVERO_GPIO_W2W_NRESET") == 0) &&
diff --git a/arch/arm/plat-omap/include/mach/board-overo.h b/arch/arm/plat-omap/include/mach/board-overo.h
index 8635171bac3..aca717d6593 100644
--- a/arch/arm/plat-omap/include/mach/board-overo.h
+++ b/arch/arm/plat-omap/include/mach/board-overo.h
@@ -18,6 +18,7 @@
 
 #define OVERO_GPIO_BT_XGATE	15
 #define OVERO_GPIO_W2W_NRESET	16
+#define OVERO_GPIO_PENDOWN	114
 #define OVERO_GPIO_BT_NRESET	164
 #define OVERO_GPIO_USBH_CPEN	168
 #define OVERO_GPIO_USBH_NRESET	183